This is Princess Bubble Moon. She is the daughter of Princess Luna and Derpy. Unlike her clumsy mom, Derpy she is a very graceful flyer, but when she tries to use her magic you'd better duck in cover. Her dream is to be able to raise the moon just like her mother, but she's got a lot of work to do with her magic before that happens.
Bubble Moon came to be when Princess Luna was raising the moon one night. Luna was flying up towards the moon when Derpy came crashing into her causing Luna's magic to involuntarily wrap around both of them. The two crashed to the ground and Luna's magic dissipated. After shaking the dizziness out of their heads, both mares looked up to see a little grey alicorn filly. Being that Derpy already had to raise two daughters by herself, Luna didn't want to put the burden of another filly on her, so she agreed to raise the young princess. She named her Bubble Moon.
Princess Bubble Moon is Mine!
She was designed by ~CottonCandyKid
Base by ~rongothepony